Good In A Pinch: The Physics Of Crimped Connections

February 9, 2017 by Dan Maloney 125 Comments

I had a friend who was an electronics assembly tech for a big defense contractor. He was a production floor guy who had a chip on his shoulder for the engineers with their fancy book-learnin’ who couldn’t figure out the simplest problems. He claimed that one assembly wasn’t passing QC and a bunch of the guys in ties couldn’t figure it out. He sidled up to assess the situation and delivered his two-word diagnosis: “Bad crimp.” The dodgy connector was re-worked and the assembly passed, much to the chagrin of the guys in the short-sleeved shirts.

Aside from the object lesson in experience sometimes trumping education, I always wondered about that “bad crimp” proclamation. What could go wrong with a crimp to so subtly futz with a circuit that engineers were baffled? How is it that we can rely on such a simple technology to wire up so much of the modern world? What exactly is going on inside a crimped connection anyway?

Continue reading “Good In A Pinch: The Physics Of Crimped Connections” →

Taking The Leap Off Board: An Introduction To I2C Over Long Wires

February 8, 2017 by Sonya Vasquez 100 Comments

If you’re reading these pages, odds are good that you’ve worked with I²C devices before. You might even be the proud owner of a couple dozen sensors pre-loaded on breakout boards, ready for breadboarding with their pins exposed. With vendors like Sparkfun and Adafruit popping I²C devices onto cute breakout boards, it’s tempting to finish off a project with the same hookup wires we started it with.

Image result for i2c sensor array — prototyping starts here, but we’re in danger when projects finish with this sort of wiring

It’s also easy to start thinking we could even make those wires longer — long enough to wire down my forearm, my robot chassis, or some other container for remote sensing. (Guilty!) In fact, with all the build logs publishing marvelous sensor “Christmas-trees” sprawling out of a breadboard, it’s easy to forget that I²C signals were never meant to run down any length of cable to begin with!

As I learned quickly at my first job, for industry-grade (and pretty much any other rugged) projects out there, running unprotected SPI or I²C signals down any form of lengthy cable introduces the chance for all sorts of glitches along the way.

I thought I’d take this week to break down that misconception of running I²C over cables, and then give a couple examples on “how to do it right.”

Heads-up: if you’re just diving into I²C, let our very own [Elliot] take you on a crash course. Continue reading “Taking The Leap Off Board: An Introduction To I2C Over Long Wires” →

Friday Hack Chat: Making And Breaking Hardware With Bunnie

February 8, 2017 by Brian Benchoff 5 Comments

This Friday, February 10th, at 9am PST, Hackaday.io will be graced with one of the greatest hardware creators in recent memory. [Bunnie Huang] will be talking about making and breaking hardware in the Hackaday.io Hack Chat.

[Bunnie] is a nearly peerless hardware hacker. He literally wrote the book on hacking the XBox, developed the Chumby, and developed the Novena, an open source Laptop. He’s torn down the Form 2 3D printer, explored the iPhone’s hackability with [Edward Snowden], wrote the book you want to have on your carryon when flying into Hong Kong, and recently released The Hardware Hacker, a retelling of his adventures in hardware hacking. He’s now working on the Love to Code platform.

[Bunnie] is a bridge across worlds. There is no one else so deeply embedded in the world of electronics manufacturing that is also willing to tell the world about what he’s found. If you want to learn about electronics, the Bunnie Studios blog is a mandatory read.

For this week’s Hack Chat, [Bunnie] will be taking questions from the Hackaday.io community. If you’ve ever wanted to know what it takes to build a few thousand things, this is the guy to ask.

Having trouble figuring out when 09:00 PST is in your local time zone? Here’s a countdown timer!

Here’s How To Take Part:

Buttons to join the project and enter the Hack Chat

Our Hack Chats are live community events on Hackaday.io Hack Chat group messaging. Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Upcoming Hack Chats

These Hack Chats are a weekly thing, and we have a few more on the books. Next week, we’ll be covering RF design with [Jenny List], and later going over mechanical manufacturing with Fictiv. You can check out all the upcoming Hack Chats on this project.

Using A Lecher Line To Measure High Frequency

February 7, 2017 by Steven Dufresne 35 Comments

How do you test the oscillator circuit you just made that runs between 200MHz and 380MHz if all you have is a 100MHz oscilloscope, a few multimeters and a DC power supply? One answer is to put away the oscilloscope and use the rest along with a length of wire instead. Form the wire into a Lecher line.

That’s just what I did when I wanted to test my oscillator circuit based around the Mini-Circuits POS-400+ voltage controlled oscillator chip (PDF). I wasn’t going for precision, just verification that the chip works and that my circuit can adjust the frequency. And as you’ll see below, I got a fairly linear graph relating the control voltages to different frequencies.

What follows is a bit about Lecher lines, how I did it, and the results.

Continue reading “Using A Lecher Line To Measure High Frequency” →

Hackaday Links: February 5, 2017

February 5, 2017 by Brian Benchoff 7 Comments

A lot of people around here got their start in electronics with guitar pedals. This means soldering crappy old transistors to crappy old diodes and fawning over your tonez, d00d. Prototyping guitar pedals isn’t easy, though, and now there’s a CrowdSupply project to make it easier The FX Development Board is just that — a few 1/4″ jacks, knobs, pots, power supply, and a gigantic footswitch to make prototyping guitar pedals and other musical paraphernalia easy. Think of it as a much more feature-packed Beavis Board that’s still significantly cheaper.

How do Communicators in Star Trek work? Nobody knows. Why don’t the crew always have to tap their badge before using it? Nobody knows. How can the com badge hear, ‘Geordi to Worf’, and have Worf instantly respond? Oh, we’ve argued about this on IRC for years now. Over on Hackaday.io, [Joe] is building a Star Trek com badge. The electronics are certainly possible with modern microcontrollers, but for the enclosure, we’ll have to review a few scenes from Time’s Arrow and The Enemy.

[Alois] was working with an Intel Edison on a breadboard. He was generating a signal, and sending it through a little tiny breadboard wire to an oscilloscope. The expected waveform should have been a nice square wave at 440MHz. What he got out of this wire was a mess. You shouldn’t use long wires when probing circuits. That little breadboard wire was a perfect radiator for 440MHz, and the entire setup turned into an antenna.

[Douglas] is running a Kenwood TM-D710A as his amateur radio rig. This radio does APRS stuff, but it requires an external GPS and power source to do it right. GPS receivers are now very small and very cheap, so [Douglas] just stuffed a GPS module inside his radio. The module itself is a GP-20U7, a tiny GPS module the size of a postage stamp, and wired it up to a few pads on the radio PCB.

Here’s an upcoming Kickstarter that’s going straight to the front page of Boing Boing. It’s Pong, in coffee table format which we first saw last Spring. Instead of racing the beam, this version of Pong is mechanical. The ball is a cube, the paddles are slightly longer cubes, and the entire game is a highly refined CNC machine. Here’s something from seven years ago that’s also Pong in coffee table format. Pongmechanik is electromechanical Pong, built entirely out of switches, relays, and a few motors.

Creating A PCB In Everything: Upverter

February 3, 2017 by Brian Benchoff 48 Comments

For the last five months, I’ve been writing a series of posts describing how to build a PCB in every piece of software out there. Every post in this series takes a reference schematic and board, and recreates all the elements in a completely new PCB tool.

There are three reasons why this sort of review is valuable. First, each post in this series is effectively a review of a particular tool. Already we’ve done Fritzing (thumbs down), KiCad (thumbs up), Eagle (thumbs up), and Protel Autotrax (interesting from a historical perspective). Secondly, each post in this series is a quick getting started guide for each PCB tool. Since the reference schematic and board are sufficiently complex for 90% of common PCB design tasks, each of these posts is a quick how-to guide for a specific tool. Thirdly, this series of posts serves as a basis of comparison between different tools. For example, you can do anything you want in KiCad and most of what you want in Eagle. Fritzing is terrible, and Autotrax is the digital version of the rub-on traces you bought at Radio Shack in 1987.

With that introduction out of the way, let’s get cranking on Upverter.

A little bit about Upverter

Upverter was founded in 2010 as an entirely web-based EDA tool aimed at students, hobbyists, and Open Hardware circuit designers. This was one of the first completely web-based circuit design tools and Upverter’s relative success has been a bellwether for other completely web-based EDA tools such as circuits.io and EasyEDA.

I would like to take a second to mention Upverter is a Y Combinator company (W11), which virtually guarantees this post will make it to the top of Hacker News. Go fight for imaginary Internet points amongst yourselves.

Upverter is a business after all, so how are they making money? Most EDA suites offer a free, limited version for personal, hobbyist, and ‘maker’ projects, and Upverter is no exception. The professional tier offers a few more features including CAM export, 3D preview, an API, simulation (coming soon), BOM management, and unlimited private projects for $125 per seat per month, or $1200 per seat per year.

To give you a basis of comparison for that subscription fee, Eagle CAD’s new license scheme gives you everything – 999 schematic sheets, 16 layers, and unlimited board area – for $65 per month, or $500 per year. Altium’s CircuitStudio comes in at $1000 for a one-year license. There are more expensive EDA suites such as Altium Designer and OrCAD, but you have to call a sales guy just to get a price.

Upverter is positioning itself as a professional tool at a professional price. There are better tools out there, of course, but there are thousands of businesses out there designing products with tools that cost $500 to $1000 per seat per year. In any event, this is all academic; the Hackaday crowd gravitates towards the free end of the market, whether that means beer or speech.

A big draw for Upverter is their Parts Concierge service. You’ll never have to create a part from scratch again, so the sales copy says. Apparently, Upverter is using a combination of very slick scripts to pull part layouts off a datasheet and human intervention / sanity check to create these parts. Does it work? We’re going to find out in the review below.

Continue reading “Creating A PCB In Everything: Upverter” →

Books You Should Read: Making A Transistor Radio

February 3, 2017 by Jenny List 33 Comments

When a Hackaday article proclaims that its subject is a book you should read, you might imagine that we would be talking of a seminal text known only by its authors’ names. Horowitz and Hill, perhaps, or maybe Kernigan and Ritchie. The kind of book from which you learn your craft, and to which you continuously return to as a work of reference. Those books that you don’t sell on at the end of your university career.

Ladybird books covered a huge range of topics.

So you might find it a little unexpected then that our subject here is a children’s book. Making A Transistor Radio, by [George Dobbs, G3RJV] is one of the huge series of books published in the UK under the Ladybird imprint that were a staple of British childhoods for a large part of the twentieth century. These slim volumes in a distinctive 7″ by 4.5″ (180 x 115 mm) hard cover format were published on a huge range of subjects, and contained well written and informative text paired with illustrations that often came from the foremost artists of the day. This one was published at the start of the 1970s when Ladybird books were in their heyday, and has the simple objective of taking the reader through the construction of a simple three transistor radio. It’s a book you must read not because it is a seminal work in the vein of Horrowitz and Hill, but because it is the book that will have provided the first introduction to electronics for many people whose path took them from this humble start into taking the subject up as a career. Including me as it happens, I received my copy in about 1979, and never looked back. Continue reading “Books You Should Read: Making A Transistor Radio” →

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Good In A Pinch: The Physics Of Crimped Connections

Taking The Leap Off Board: An Introduction To I2C Over Long Wires